Q. 4

$Earth \, is \, 1.5 \times 10^8 km \, from \, sun Mercury \, is \, 5.81 \times 10^7 km from \, sun$

How much nearer is the sun to mercury than to the Earth ?

$Sun \, to \, Mercury : Sun \, to \, Earth 5.81 \times 10^7 : 1.5 \times 10^8 5.81 \times 10^7 : 15 \times 10^7 \Rightarrow 15 \times 10^7 - 5.81 \times 10^7 \Rightarrow 9.19 \times 10^7$
$1 Terametre = 10^{12} m$

Find distance of Earth from Sun in Terametre

$Earth \, from \, sun = 1.5 \times 10^8 km = 1.5 \times 10^8 \times 1000 = 1.5 \times 10^{11} m Distance \, in \, Terametre = 1.5 \times 10^{11} \div 1 \times 10^{12} = 1.5 \times 10^{-1} = 0.15$